A: Possibly. Many cracked/abandonware files use packers that mimic malware. If you downloaded from a reputable abandonware site, add the game folder to your antivirus exclusions.
Since a 5th installment doesn't exist, here is what defined the most recent version, , which you might be searching for: Star Defender 5 For Pc
Automatically lock onto the fastest targets on screen, allowing you to focus entirely on dodging incoming fire. A: Possibly